This release adds the IO.trysplice and IO.trytee interfaces
to avoid expensive EAGAIN exceptions for non-blocking I/O.

There is no IO.tryvmsplice method as we still haven't figured
out a good use for IO.vmsplice in Ruby, and non-blocking I/O
with iovecs is just painful! If you want more zero-copy fun
without needing mmap(2), check out the "sendfile" RubyGem and
IO.copy_stream (1.9). As of Linux 2.6.33+, sendfile(2) can copy
mmap-able files to +any+ descriptor, not just sockets.

Please email us at ruby.io.splice@librelist.com if you can think
of a good use for IO.vmsplice or IO.trysplice in Ruby.